Cylinder housing

ABSTRACT

A lock cylinder of a motor vehicle has a cylinder housing formed from plastic and the cylinder housing has an opening for receiving a cylinder core. The plastic of the cylindrical housing is reinforced at least in certain regions with aramid fibers. Thus, the cylinder housing is extremely robust and increases the forcing resistance of a door lock equipped therewith.

CROSS REFERENCE TO RELATED APPLICATION

This application claims priority under 35 USC 119 to German Patent Appl.No. 10 2012 111 606.7 filed on Nov. 29, 2012, the entire disclosure ofwhich is incorporated herein by reference.

BACKGROUND

1. Field of the Invention

The present invention relates to a cylinder housing for a lock cylinderof a motor vehicle. The invention also relates to a motor vehicleequipped with at least one such cylinder housing.

2. Description of the Related Art

Lock devices for motor vehicles usually have a cylinder housing and acylinder core is mounted rotatably in the cylinder housing. The cylinderhousings known from the prior art are produced, for example, from metal,in particular in a zinc die casting process. Such cylinder housings haverequired mechanical properties, but are relatively expensive to produceand have a high weight.

DE 10 2008 001 627 A1 discloses a cylinder housing for a lock cylinderof a motor vehicle. An opening is arranged in the longitudinal directionof the cylinder housing and a cylinder core can be received in theopening. The cylinder housing is formed from plastic, but has anembedded reinforcing inlay formed from a material stronger than theplastic. This has the aim of producing a strong, low weight cylinderhousing that spares raw material resources, in particular metallic rawmaterial resources.

EP 1 053 918 A2 discloses a long-fiber-reinforced plastic housing for alock cylinder of a motor vehicle.

DE 25 36 804 A1 discloses a cylinder housing for a lock cylinder of amotor vehicle where the cylinder housing is made of plastic withembedded glass fibers.

DE 31 34 471 C2 discloses a cylinder housing made of plastic withembedded carbon fibers.

EP 0 655 539 B1 and DE 299 12 034 U1 disclose fiber-reinforced lockparts for lock devices of a motor vehicle.

An object of the invention is to provide a cylinder housing that isdistinguished by a lightweight and extremely strong design.

SUMMARY OF THE INVENTION

The invention relates to a cylinder housing for a lock cylinder of amotor vehicle. The cylinder housing is formed from plastic and theplastic is reinforced at least in certain regions with aramid fibers orfibers having comparable properties. Aramid fibers of this type arecommonly also known under the name “Kevlar fibers”. Aramid is in thisrespect generally a designation for aromatic polyamides, and thesepolymer materials have a similar structure to proteins. According to adefinition of the US Federal Trade Commission, only those long-chainsynthetic polyamides in which at least 85% of the amide groups are bounddirectly to two aromatic rings are designated as aramids. In generalterms, aramid fibers are distinguished by a very high strength, highimpact strength, a high elongation at break, good vibration damping andalso a first-class resistance to acids and alkalis. They areadditionally heat-resistant and flame-resistant and do not melt at hightemperatures, but rather begin to carbonize from a temperature ofapproximately 400° C. The reinforcement of the cylinder housing byaramid fibers makes it possible to increase the strength of the cylinderhousing considerably, with a weight that is reduced considerablycompared to metallic cylinder housings.

The invention also increases break-in resistance considerably,particularly in the region of screw-on points where the cylinder housingis screwed onto the motor vehicle. Reinforcing such screw-on points witharamid fibers increases the stability of the lock device as a whole.

The aramid fibers preferably are embedded in or laminated onto theplastic of the cylinder housing. The aramid fibers can be embedded, forexample, by insertion into an appropriate plastics injection mold, wherethe aramid fibers can be configured, for example, as woven fabric pliesthat provide an internal reinforcement of the cylinder housing.Alternatively, the aramid fibers can be laminate to the plastic of thecylinder of the housing by both cold and/or hot lamination. In bothcases, the aramid fibers, which may be configured as a woven fabric ply,may be bonded to the plastic cylinder housing by an adhesive layer. Thelamination of the aramid fibers onto the cylinder housing made ofplastic has the major advantage that, depending on the equipmentvariant, the cylinder housing can be installed optionally with orwithout additional aramid fibers, thereby giving rise to a relativelyflexible production process. The cylinder housing is provided withoutadditional aramid fibers in the case of certain equipment variants,whereas aramid fibers are laminated on cylinder housings in higher-valueequipment variants.

The plastic of the cylinder housing may be reinforced with embeddedcarbon fibers. Carbon fibers are industrially produced fibers made fromcarbon-containing starting materials that are converted, by pyrolysis,into carbon in graphite configuration. The diameter of carbon fibers isusually between 5 and 8 μm, with several thousand such individual fibers(filaments) being combined to form a roving. Carbon fibers aredistinguished by a high strength and a low weight and as a result aresuitable in particular for reinforcing plastic components. Carbon fibersof this type may be configured in the manner of woven fabrics and, likecomparable aramid woven fabrics, form particular protection againstpenetration. In this case, it is of course possible, depending on thedesired strength, for a plurality of carbon fiber plies or aramid fiberplies to be arranged one above another in or on the cylinder housing.

Further important features and advantages of the invention becomeapparent from the drawings and from the associated description of thefigures with reference to the drawings.

The features mentioned above and those still to be explained below canbe used not only in the combination given in each case but also in othercombinations or on their own, without departing from the scope of theinvention.

Preferred exemplary embodiments of the invention are shown in thedrawings and are explained in more detail in the following description,where the same reference signs refer to identical or similar orfunctionally identical components.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional illustration through a cylinder housing accordingto the invention with a lock cylinder arranged therein.

FIG. 2 is an oblique view of a cylinder housing according to theinvention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 shows a lock device 1 for a door lock of a door of a motorvehicle, the lock device 1. The lock device 1 has a cylinder housing 2and a lock cylinder 3 arranged therein. The cylinder housing 2 is formedfrom plastic that is reinforced at least in certain regions with aramidfibers 4. In this case, the aramid fibers 4 can be embedded in theplastic of the cylinder housing 2, as is shown in FIG. 1 or can belaminated onto the plastic of the cylinder housing 2, as shown in FIG.2. In both cases, the aramid fibers 4 stiffen or reinforce the cylinderhousing 2 and additionally afford effective shatter protection. Thus,the cylinder housing 2 and particularly screw-on points 5 will not bedestroyed by the action of a misuse force, for example when forcing thelock device 1. The screw-on points 5 are shown in FIG. 2 and functionfor the screwing of the lock device 1 onto the motor vehicle (notshown), for example onto a shell of a motor vehicle door.

The aramid fibers 4 can be embedded in the plastic of the cylinderhousing 2 by inserting the aramid fibers 4 into a plastics injectionmold and encapsulated the aramid fibers 4 by the plastic upon injectionmolding of the cylinder housing. As an alternative, the aramid fibers 4can be laminated on and bonded to the cylinder housing 2 by an adhesivelayer. The aramid fibers 4 can be bonded to the cylinder housing 2 asindividual strands of fiber or as a woven fabric. The lamination affordsthe major advantage that the layer containing the aramid fibers 4 isapplied merely purely optionally to the cylinder housing 2, so that thelatter can be provided optionally with or without aramid fibers 4, forexample depending on the value of the equipment line.

In addition to the aramid fibers 4, the cylinder housing 2 can bereinforced with further fibers, for example with carbon fibers 6 or withglass fibers 7. These are usually embedded in the plastic of thecylinder housing 2.

The cylinder housing 2 of the invention makes it possible to provide acomponent in particular with a considerably increased strength andresistance, which in particular also contributes to increasing the theftprotection of a motor vehicle equipped with such a lock device 1 or withsuch a cylinder housing 2.

What is claimed is:
 1. A cylinder housing for a lock cylinder of a motorvehicle, the cylinder housing comprising: a hollow cylindrical wall forholding the lock cylinder therein and mounting flanges projecting outfrom the cylindrical wall, screw-on points formed on the mountingflanges for mounting the cylinder housing to the motor vehicle, thecylinder housing being formed from plastic reinforced with a wovenfabric of aramid fibers laminated onto the mounting flanges forproviding shatter protection of the screw-on points against an action ofmisuse force.
 2. The cylinder housing of claim 1, further comprisingaramid fibers embedded in the plastic of the cylinder housing.
 3. Thecylinder housing of claim 1, further comprising carbon fibers or glassfibers embedded in the plastic.
 4. A theft-protected motor vehicle,comprising: a door; a cylinder housing having a hollow cylindrical walland screw-on points secured to the door of the motor vehicle; a lockcylinder disposed in the hollow cylindrical wall of the cylinderhousing; and a reinforcing fabric comprising aramid fibers laminated toat least regions of the cylinder housing having the screw-on points toprovide shatter protection to at least areas of the cylinder housingsecured to the door of the vehicle to protect against an action ofmisuse force.
 5. The motor vehicle of claim 4, wherein the cylinderhousing is made of plastic and has carbon fibers embedded therein.
 6. Alock adapted to be mounted to a motor vehicle, comprising: a cylinderhousing having a hollow cylindrical wall and mounting flanges projectingout from the cylindrical wall, screw-on points formed on the mountingflanges for mounting the cylinder housing to the motor vehicle, thecylinder housing being formed from plastic with carbon fibers or glassfibers embedded therein; a lock cylinder disposed in the hollowcylindrical wall of the cylinder housing; and a reinforcing fabriccomprising aramid fibers laminated to at least the mounting flanges ofthe cylinder housing for providing shatter protection of the screw-onpoints against an action of misuse force.